Conversion of higher boiling hydrocarbons to lower boiling hydrocarbons



Sept. 22, 1936.

v. HENNY CONVERSION OF HIGHER BOILING HYDROCARBONS TO LOWER BOILING HYDROCARBONS Original Filed May 7, 1 933 int . H. I WUV O lliil III I flH l l l IHl ul PH "I I I lllxllllllllhnU,

.Z/VVENTOQ I/z'cfor Hem? WOZ J41 ATTO/QN- Y Patented Sept. 22, 1936 UNITED STATES PATENT, OFFICE CARBONS To, CABBONS LOWER BOILING HYDRO- Victor Henny, London, England, assignor,.l.by .mesne assignments, to Universal Oil Products Company, Chicago,

Ware V 111., a corporation of Dela,-

Application May 1; 1936, Serial No; 450,329

Renewed July25,1935" p 4 Claims (01. 196-48) This invention-relates to the conversion of higher boiling hydrocarbons to lower boiling hycracking stock from the-vapors and gases derived from the carbonizat'ion of bituminous materials and the conversion 'of same at elevated temperatures in" the vapor phase into anti-knock motor fuel and other. products.

It is among the'objects of'my invention to make use of low grade coals 'and coal wastes as well as the higher grade coalsinthe production of coke and high anti-knock motor fuel. The carbonaceous materials used include bituminous coals, cannel coal, brown coal, lignites, peats, etcetera. My inventionis directed particularly toward the treatment of the condensable vapors produced in the :c'arbonization of: these materials.

Among further objects of my invention is to provideaprocess where the carboniz'ation process andcrackin'g operation are combined, i. e., a processv where the vapor and gaseous products from the carbonaceous process are treated and a tar oil suitableascracking.stock separated and subjectedto conversion conditions. Advantages are obtained such as heat economy, reduction or elimination of high coke-forming constituents in the cracking stock,imp'roved yields and quality of the products, etcetera. r 1 I The carbonization stage of the process is preferablyof the low temperature type inwhich the carbonaceous inaterial'is subjected to the relatively low temperature treatment of approximately 750-1000 F. whereln'gher yields of oil for cracking are obtained than in high temperature carbonization and decreased yield of coke and gaseous products. The 'coke is'a desirable, smokeless fuel and'the gases have a much higher heating value than the gases'obtained in'high temperature carbonization.

My invention comprises the treatment of the vaporand gaseous products from the carbonizatio'n pro'cess,separating the uneondensable gases and light "condensable' fractions which include 'movedso as not to contaminate the intermediate product. 'Elimination of this heavy oil increases 'the'length of the operating'cycle in the conversion stage,- cutsdown' the coke and gas production, and increases the total liquid recovery from the operation. The intermediate fractions are separated, condensed and. directed to the conversion-stage of the r process without cooling, thus affording heat economy.

' The invention" will be more clearly understood by referring to the attached drawing which will bed'escribed later" and in which the preferred embodiment of the conversion stage is illustrated. Temperature conditions used in the conversion zone may vary from 900 to 1400 F.,-more or less, and the pressure may vary from superatmospheric pressure to atmospheric or sub-atmospheric pressure. Pressures on the system may be uniform, varying only as a result of the friction or natural pressure trap through the various elements, ordifferential pressures may be used by manipulation of ;the various valves orother means indicated l 9 I Referring now to the attached drawing, which is a diagrammatic side elevation, not drawn toy I scale, the tar oil vapors from the retorts: of a continuous carbonization process (not shown) are introducedthrough line I and valve2 to the fractionatingcolumn; 3 where the vapors are separated into several fractions. Cooling means are introduced through line 4 as will be later described. The-heavy condensate oil flows downward through line 5 and valve 6 to the suction side of the hot'oil pump 1 which pumps this oil through line" 8:'Whi0h leads'to storage or other suitable disposal. Uncondensed vapors and unrcondensable gases leave the topof the fractionating column 3 through line 9 and valve I I], pass to the condenser and/or cooler H and are then directed through-line- I2 and valve I3 to the receiver M- where separation of the liquid and gases is effected. .The non-condensable gases are removed through line l5, regulated by valve l6, and the liquid is removed through line I! regulated by valve I8. 7

p ,A regulated portion'of the liquid product in receiver may be directed through line 19 and valve 80 to the suction side of pump 8| and pumped through line 82 and valve 83 to the top of the fractionating column 3. The intermediate fractions or side cuts leave the fractionating col umn 3 through lines I 9 and 20 and by the suitable are directed'intodine which leads to the surge drum 25. If it is so desired intermediate fractions may be removed as may be illustrated through line l9 with valve 2| open and valve 22 in line 24 closed, may be directed to cooling means or other suitable disposal. The surge drum 25 is vented by means of line 26 with valve 21 which connects preferably to the top of the fractionating column 3. The tar oils in the surge drum 25 flow downward through line 28 and valve 29 to the suction side of pump 30 which pumps this oil through line 3| which leads to the heating or vaporizing zone through valve 32 or to the vaporphase heating coil outlet through line 33, reignlated by valve 34. Where tar oil passes through line 3| and valve 32 it mixes with reflux condensate oil from the dephlegmator 54 and passes to the heating or vaporizing zone 35 which may be located in the convection zone '36 of a radiant heat furnace 31 where the oilis heated and vaporized and passes through line 38 leading into the line 39 from which it may be directed through valve 40 into the knock-out drum 4| or through" valve 42 into the vapor line 43 from the knock out drum. Hydrocarbon oil from any source may be introduced to the process through one or more suitable places, such as through valve 32" in line 3|, through valve 2" in line or through valve 34' in line 33.

Heavy oil is withdrawn from the knock-out drum 4| through line 44,-'regulated by valve 45, which leads through a cooler (not shown) to storage or other suitable disposal. The vapors leave the knock-out drum 4| through line 43, regulated by valve 44 and pass to the vapor-phase cracking zone 45 located in the heating zone 46. The high temperature vapors leave the zone 45 through line 47 which leads through valve into the knockout drum 49. Heavy oil is removed from the knock-out drum 49 through'line 50 regulated by valve and mixes with heavy oil from the knockout drum 4| in line 44. The cracked vapors and gases leave the drum 49 through line 52 and valve 53 and enter the dephlegmator 54 where a separation of heavier fractions from the lighter fractions is effected. The heavier fractions condense in dephlegmato-r 54, reflux condensate, so-called, flow downward through line 55 and valve 56 where valve 51 may be closed so that the oil flows through line 58 and valve 59 to the suction side of pump 60 which pumps this oil through line 6| and valve 52 to the heating coil 35 as previously described. The continuation of line 55 beyond 51 leads to a cooler coil (not shown) and to storage or other suitable disposal. The vapors'and uncondensable gases leave the dephlegmator 54 through line 62 with valve 63 leading to the condenser and/or cooler 64 and then passing through line 55 and valve 66 to the receiver 61 where separation of the liquid product and uncondensable gases is effected. The uncondensablegases are removed through line 68 regulated by valve 69 and the liquid oil product is removed through line 1'0 regulated by valve 1|. Water is withdrawn through line 12 regulated by valve 13; Any desired portion of the oil product may be directed through line" and-valve 15 to the suction side of pump 15 which pumps this oil through line 11, regulatedby valve 18, to the top of the dephlegmator 54..

As an illustration of the operation of the process of my invention'and the results obtained'in connection'with a continuous low temperature carbonization process where a bituminous coal is being' processed, the vapors and gases produced are directed'to the fractionating column 3 d g matically illustrated in theodrawing above described.

Approximately 8% of the total condensable materials pass over to the condenser together with the uncondensable gases and are separated and withdrawn as motor fuel stock. Pitch and heavy viscous oil amounting to approximately 35% of the total condensable materials are condensed and drawn off from the bottom of the fractionating column 3 through line 5 and discharged by the hot residue pump I through a cooler to storage or directly to the pitch bench. The intermediate fractions amounting to approximately 5557% of thetotal condensable materials are removed as side streams-from the fractionating column and collected in surgedrum 25 from which they are pumped by an automatically controlled hot feed pump which discharges the tar oils into the outlet line from the vapor phase cracking zone where it retards the reaction and prevents the deposit of coke.

Thereflux condensate from the dephlegmator 54 which consists of unconverted and partially converted hydrocarbons is pumped by means of the hot oil pump which is also automatically controlled-and is pumped through the preheating tubes wherethetemperatureat the outlet is approximately 850 F. The temperature in the vapor-phase cracking coil outlet is approximately 1150 F. and the pressure approximately '70 pounds. The temperature of approximately 550 F. is maintained at the top of the dephlegmator by recirculating the distillate produced therefrom and collected in receiver 61.

The refined motor fuel resulting from this operation represents approximately 40% based on the oil charged to the conversion stage of the process. The motor fuelhas an end point of approximately 400" F. and has an anti-knock value of approximately 70% benzol in Pennsylvania straight-run gasoline. The heavy liquid fractions removed'from the knock-out drums constitute a satisfactory fuel oil which represents 35% based on the oil converted.

My invention should not be construed as being limited to the above illustrated operation or to the yields and character of products described therein.

I claim as my invention:

1. A process for producing anti-knock motor fuel from hydrocarbon oil and vapors obtained in the destructive distillation of solid carbonaceous materials which comprises condensing said vapors to form a liquid distillate, vaporizing the hydrocarbon oil in a vaporizing zone and then subjecting the'same to vapor phase cracking conditions of temperature and pressure in a cracking zone and removing resultant cracked vapors, injecting said distillateinto the hot cracked vapors removed from the cracking zone, dephlegmating the resultant vaporous mixture independently of the. first-named vapors to condense heavier fractions thereof as reflux condensate, supplying the reflux condensate to the vaporizing zone, and finally condensing the dephlegmated vapors.

2. A process for producing anti-knock motor fuelfrom the vaporous' mixture produced in the destructive distillation of solid carbonaceous material, which comprises fractionating said mixture in a dephlegmating zone and separating therefrom a tar oil heavier than gasoline, simultaneously fractionating cracked vapors, formed as hereinafter set forth, independently of said mixture in a second dephlegmating zone to condense and separate heavier fractions thereof, vaporizing resultant reflux condensate and cracking the same in the vapor phase, commingling said tar oil 4. The process as defined inclaim 2 further characterized in that a hydrocarbon oil cracking stock, from a source other than said vaporous mixture, is vaporized and cracked in admixture with said reflux condensate, said cracking stock being combined with the reflux condensate by introduction into contact with the cracked vapors undergoing fractionation in the second dephlegmating zone.

VICTOR HENNY. 

